Regulating apparatus



Feb. 9, 1943. w. H. SMITH- REGULATING APPARATUS Filed May 20, 1942 WITNESSES:

lNVENTOR Patented Feb. 9, 1943 2,310,876 REGULATING APPARATUS Walter H. Smith, Wllkinsburg,

Pa., assignor to Westinghouse Electric 8; Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application May 20, 1942, Serial No. 443,686 Claims. (Cl. 290-17) This invention relates to regulating apparatus for constant speed engines, and particularly to regulatingitapparatus for preventing overloading of constant speed engines.

In Diesel electric locomotives it is necessary to provide for load regulation to prevent overloading of the Diesel engine. Many types of load regulating apparatus have been provided heretofore but they have had certain disadvantages. The difl'erent types of known load regunected pressure responsive pile resistor 32 and adjustable field rheostat 34 to be energized from v a suitable source of power such as the battery 35.

lating apparatus are complicated and have large moving parts thereby necessitating more space for mounting the regulating apparatus and thereby greatly adding to the cost of the installation. Another disadvantage of the known types of regulators is that hunting is encountered whereby the control is not sufficiently sensitive to meet given conditions.

An object of this invention is to provide for operating constant speed engines at substantially maximum capacity without overloading and stalling them.

Another object of this invention is to provide anti-hunting regulating apparatus for constant speed engines to maintain the operation of such engines at substantially maximum capacity without overloading and stalling them.

Other objects of this invention will become apparent from the following description when taken in conjunction with the accompanying drawing in which:

Figure 1. is a view in elevation and partly in section of control apparatus employed in this invention, and v Fig. 2 is a schematic view of the regulating apparatus of this invention.

Referring to Fig. 2 of the drawing, the preferred embodiment of the regulating apparatus is illustrated applied to a Diesel engine Ill. The

Diesel engine in is of the usual type having hand or power operated throttles (not shown) for controlling the operation of the engine and a speed governor l2 for preventing'overloading of the engine as will be explained more fully hereinafter.

A generator l4 provided with an armature winding l6 and a field winding I8 is driven by the Diesel engine In. The armature windings l6 are connected through an operating switch to a motor 22. The field winding I8 of the generator' I4 is electrically connected through a suitable adjustable resistor 24 to the armature 26 of an exciter generator 28 which is also driven by the Diesel engine. The exciter 28 also has a field winding 30 connected through a series-con- The pile resistor 32 and the operating mechanism therefor is better shown in Fig. l.

The pile resistor 32 comprises a stack of disks 38 slidably mounted on an insulated rod 40 between pressure disks 42 and 44, and can be mounted on the panel 46 in any suitable manner. Although only one stack of disks 38 is visible in Fig. 1, usually two or more stacks connected in series circuit relation are utilized and are so mounted that an equalized pressure can be applied simultaneously to each stack. The ends of the rod 40 are slidably mounted in the support members 48 and 50 carried by the panel, a spring member 52 being provided for normally biasing the rod 40 away from the fixed stop 5 carried by the support 50 at the other end of the stack.

A pressure applying lever 58 is pivotally carried by an anchor stud 58 which is secured to a lug 60 carried by the support member 48. A pressure spring 62 ispositioned between the lug 60 and the lever 56 for normally biasing the lever 56 to apply'pressure to the cross bar 64 where more than one stack is employed, or directly to the end cap of the pressure disk 42 to compress the stack of disks. Pile resistors of this general type are disclosed and claimed in my Patent No. 2,276,069, issued March 10, 1942, and assigned to the assignee of this invention.

In order to release the pressure on the stack of disks 38, a control valve member 66 and a power piston 68 are provided for so cooperating in response to a decrease in the speed of the engine M as to apply pressure to the end of the lever 56 in opposition to the pressure of the spring 62.

The control valve member 66 is formed of a plurality of elements and comprises the casing member 10, a sleeve valve 12 and a piston valve member 14, the casing member and sleeve valve being provided with suitable ports and passages ,for effecting a predetermined operation of the power piston 68;

The piston valve member 14 is provided with the valve 16 disposed intermediate of the closure members 18 and 80, and is operatively positioned in the sleeve valve member 12. A passage 82 is provided in the piston valve member extending from the upper end thereof and terminating in the opening 8| which opens into the drain chamber 86 in the casing member 10. The piston valve member is maintained in operative position in the sleeve valve member I2 by reason of the spring member 88 disposed between the end caps 90 and 92 for normally biasing the piston valve member I4 downwardly against the stop 94 carried by the casing member I0. As illustrated, a suitable oil gland 96 is provided adjacent the lower end of the piston valve member I4 for preventing leakage from the chamber 86. The sleeve valve member I2 is disposed in the casing member I for sliding movement relative to the casing member I0 and the piston valve member I4. In order to obtain a predetermined operation of the power piston, as well as the control valve member 66, the sleeve valve 12 is provided with aligned ports 98 and I00 which communicate with the chamber formed between the closure member 18 and the valve I6 of the piston valve member, a port I02 normally aligned with the valve I6 of the piston valve member, and aligned ports I04 and I06 communicating with the chamber formed between the closure member 80 and the'valve I6 of the piston valve member 14. The ports 98 and I00 are connected by the groove 99 and the ports I04 and I06 are connected by the groove I to insure communication between the connected ports. A piston I08 is also seated on the upper end of the sleeve valve member I2 disposed to be actuated to effect a movement of the sleeve valve member 12 in a predetermined manner. 1 In order to maintain the sleeve valve I2 and the piston I08 in the normal operative position, the piston is positioned about the valve stem III] and is secured in such position by the ring collar I I2 which is keyed to the stem by the key I I4. A bushing II6 having one flanged end is secured in the casing by the set screw III, the other end of the bushing being closed by the collar II8 which is secured in the casing by the set screw II9. Within the bushing, a compressing spring member I20 is disposed between the flanged collars I22 and I24 the lower collar I22 seating against the upper end of the collar I I2. As illustrated clearance is provided between the edge of the flanged end of the bushing I I6 and the collar I I2 to form the passage I26 and passages I28 are provided through the collar H8 and the flange collar I24, the purpose of which will be explained more fully hereinafter.

A reservoir I30 is formed adjacent the passages I28 by means of the end cap I32 secured to the casing member I0 and disposed about the stem member 0. The stem H9 is provided with a passage I36 which forms a drain from the reservoir I30 and is aligned with a similar passage of the piston I08 and the upper part of the sleeve valve member I2.

As illustrated, port I06 of the sleeve valve member I2 is normally disposed to be aligned with a passage I38 which is disposed to be connected by means of the pipe I40 through a pump I42, illustrated in Fig. 2, to the reservoir of the engine I0. Port I04 of the valve sleeve member I2 is disposed to normally align with one end of a U -shaped passage I44, the other end being alignedwith the port 98. As illustrated, a needle valve I46 is provided in the passage I44, the purpose of which will be explained more fully hereinafter. A passage I48 is also provided on the other side of the casing member, one end of the passage terminating in the port I00 of the sleeve valve I2 to a movement of the piston I64.

and the other end terminating in a. passage leading to the reservoir I30 at the top of the casing member III. A passage I50 is also provided in the casing member 10 terminating in a chamber I52 below the sleeve valve piston I08. Another passage I54 isprovided having one end in communication with the passage I58 and the other end communicating with the chamber formed by the bushing H6 and the collar member H6. As illustrated, a needle valve I56 is also providedin passage I54 the purpose of which will be explained more fully hereinafter. For purposes of draining the chamber 86, a passage I58 is provided in the casing member I0, and is connected by pipe I60 to the reservoir of the engine III.

The power piston member 68 is formed of the sleeve I62 having the piston I64 slidably disposed therein, a passage I66 being provided in the clo- I power piston member 68, a collar I16 is adjustably secured to the piston rod in by the setscrew Il8 the collar I16 :being disposed for abutting the lever 56 to effect a movement thereof in response The P wer piston member 68 is provided with suitable vent plugs I and I8I for filling the chambers therein with oil or for removing air from the piston member.

As illustrated in the drawing, an auxiliary piston member I82 formed of the casing I83 and the auxiliary piston I84 is so disposed on the panel 46 that the piston I84 is disposed to be actuated by the piston I64 of the power piston member 68. The auxiliary piston I84 of th auxiliary piston 'member I82 is secured to and carried on the end of the piston rod H2 in any suitable manner. The piston rod Il2 has a passage I13 therethrough extending between the vent I86 in the power piston member 68 and the vent I88 in the auxiliary piston member I82. Anoil gland I90 is provided about the piston rod I12 to prevent leakage of oil from the auxiliary piston member I82, the other end of the auxiliary piston member being connected through a passage I92 to the pipe I94 which connects with the passage I50 oi the control valve member 66. For purposes of draining the oil from the chamber formed between the piston I84 and the oil gland I90 of the auxiliary piston member I8, a passage I96 is provided in the casing connected by means of the pipe I98 to the passage 200 in the casing III. The passage 290 opens into the chamber formed byzthe bushing II8 and the end collar member I2 Again referring to Fig. 2 of the drawing, the end of the piston valve member I4 is illustrated as being in position to be actuated by the lever 20I which is pivotally mounted on the engine I0 and disposed to be actuated by the governor I2. Other suitable apparatus (not shown) may be provided for operating the piston valve member I4 of the control valve member 66 in response to diflerent speeds of the engine I8, the showing made in. Fig. 2 being merely for the purpose oi illustrating the application of this invention for valve member I2.

erated to close the circuit from the armature winding I6 to the motor 22. It is, of course, to

be understood that prior to this time the lubri- Under such circumstances, the control valve' member 66 is preheated since the lubricant of the engine I0 is delivered to the control valve through the pipe I40, passage I38, to the chamber formed between the piston valve I6 and the end closure member 80 of the piston valve member 14. The hot oil normally employed as the lubricant bleeds past the needle valve I46, the setting of which can be regulated to determine the leakage therepast,

through the passage I44 into the chamber formed between the piston valve I6 and the end closure member I8 of the piston valve member I4, and from thence to the port I00 and passage I48 to the reservoir I30. The lubricant is drained 1 through the passages I36 and 82 to the drain chamber 86 and returns from thence to the reser voir of the engine I0 by way of the passage I58 and the pipe I60. The admission of the warm lubricant in this manner preheats the components of the control valve member 66 so that it operates efficiently when the speed of the engine I0 changes.

If an excessive load is encountered such as where a locomotive is pulling a grade, the demand on the generator I6 tends to overload the engine I0 so that a decrease in the speed of the engine I0 from the speed which it is desired to maintain results. As the speed of the engine I0 decreases,

the governor I2 functions to force the lever I to actuate the piston valve member I4 upwardly against the bias of the spring 88.

As the piston valve I6 moves past the port I02 in the sleeve valve member I2, the lubricant in the chamber formed between the valve I6 and closure member 80 is delivered under pressure to the power piston member 68 through the port I02, passage II0, pipe I68 and the passage I66. The pressure thus applied to the piston I64 forces the piston I64 to actuate the lever 56 to decrease the pressure on the stack of disks 38 of the pile resistor 32. At the same time the connecting piston rod II2 effects the operation of the auxiliary piston I84 to force the lubricant originally contained in the chamber between the piston I84 and its closure member through the passage I92, pipe I34 and passage I50 of the casing member I0 to the chamber I52 below the piston I08 of the sleeve The application of the pressure to the piston I08 forces the sleeve valve member I2 upwardly against the bias of the spring I20 to a position where the port I02 comes in alignment with the piston valve I6 to prevent further delivery of the lubricant to the power piston I64. The pressure on the piston I08 will be gradually released as the lubricant bleeds from the-chamber I52 through the passage I54 past the needle valve I56 to the chamber formed by the bushing H6 and the end collar member H8 and thence through passages I28 to the reservoir I30. The period of time for such drainage can be regulated by the setting of the needle valve I56.

As the pressure is released on the carbon pile resistor 32, the resistance of the resistor 32 is increased to efiect a decrease in the field current of the exciter 28 and consequently a decrease in the field current of the generator I4. This decrease in the field current of the generator l4 effects a decrease in the voltage generated by the generator to relieve the overload condition on the engine I0. However, as in most cases, the slight movement of the power piston I64 to release the pressure on the pile resistor 32 is insuflicient, because of the simultaneous movement of the piston I84, to sufiiciently reduce the resistance of the resistor 32 as to relieve the overload condition on the engine I0. Thus, as the slide valve member 72 is returned to its normal position by reason of the bleeding of the lubricant from the chamber I52 beneath the piston I08, the port I02 again becomes open to permit the delivery of the lubricant to the power piston I 64 to effect another operation of the lever 56 to release additional pressure from the pile resistor 32. Again the lubricant is simultaneously forced by the auxiliary piston I 84 into the chamber I52 to actuate the piston I08 to again raise the sleeve valve member I2 to a position where the delivery of the lubricant to the power piston is interrupted. This cycle is repeated intermittently until the pressure on .the pile resistor has been so reduced as to remove the overload condition from the engine I0. As will be evident, the increments of pressure applied to the power piston can be so controlled as to be very small, and thereby pre' vent the removal of too much pressure from the pile resistor 32 and prevent over-control of the excitation of the generator.

As the engine I0 is brought to the desired speed, the governor I2 and the lever 20I function to release the pressure on the piston valve member I4 whereby the valve member I4 returns to the position shown in Fig. 1. However, the sleeve valve member 12 is still maintained in its upward position by reason of the pressure of the lubricant on the piston I08 which has not had a chance to bleed oil past the needle valve I56. Consequently, the lubricant retained between the power piston I64 and its closure member drains backward through the pipe I68 and passage II0 through the port I02 to the chamber formed between the piston valve 76 and its end closure member I8, and from thence through the port I00 and passage I48 to the reservoir I30. The removal of the pressure from the power piston I64 permits the spring member 62 to exert pressure through the lever 56 on the pile resistor 32. If this increase in pressure so decreases the resistance of the pile resistor 32 as to effect an increase in the voltage generated by the generator I4 to thereupon place an overload on the engine I0, then the governor I2 and the lever 20I again function to efiect an operation of the piston valve member 14 to again initiate the cooperative operation of the control valve member 66, power valve member 68 and auxiliary piston member I62 to again give a step-by-step operation of the rheostat to maintain the speed of the engine substantially constant over the changing load conditions.

By means of the regulating apparatus of this invention, it is apparent that a substantially constant speed is maintained for constant speed engines without overloading the engine regardless of the load demand on the generator driven by the constant speed engine. At all times, the power supplied by the generator is substantially constant, the voltage of the generator varying in accordance with the increase in current demand, while the speed of the prime mover for the generator remains substantially constant. The epparatus inherently prevents hunting and prevents over-control of the excitation of the generator.

Although this invention has been described with reference to a particular embodiment thereof and particularly the embodimen in which the lubricating oil of the engine is utilized as the pressure medium it is of course understood that other fluids under pressure and disposed to be heated where required can be used if they are in a closed system with the control valve, power piston and auxiliary piston member. This invention is therefore not to be limited except in so far as is necessitated by the scope of the appended claims.

Iclaim as my invention:

1. In regulating apparatus for constant speed engines, in combination, a generator provided with an armature winding and a field winding disposed to be driven by the engine, means for energizing the field winding of the generator, a rheostat connected in circuit relation with the energizing means disposed to be operated for. controlling the voltage generated by the generator, a pressure responsive means disposed for operating the rheostat, a power piston disposed to operate the pressure responsive means, a control valve responsive to the speed of the engine for efiecting the operation of the power piston, and means responsive to the operation of the power piston disposed to operate the control valve to effect the intermittent operation of the power piston to give a step-by-step operation of the rheostat to prevent over control of the excitation of the generator and maintain the speed of the engine substantially constant under changing load conditions.

2. In regulating apparatus for constant speed engines, in combination, a generator provided with an armature winding and a field winding disposed to be driven by the engine, means for energizing the field winding of the generator, a rheostat connected in circuit relation with the energizing means disposed to be operated for controlling the voltage generated by the generator, a pressure responsive means disposed for operating the rheostat, a power piston disposed to operate the pressure responsive means, a control valve responsive to the speed of the engine for effecting the operation of the power piston, an auxiliary piston associated with the power piston and responsive to movement thereof, and means associated with the control valve responsive to a movement of the auxiliary piston disposed to operate the control valve to effect the intermittent operation of the power piston to give a step-by-step operation of the rheostat to prevent over-control of the excitation of the generator and maintain the speed of the engine substantially constant urider changing load conditions.

3. In regulating apparatus for constant speed engines, in combination, a generator provided with an armature winding and a field winding disposed to be driven by the engine, means for energizing the field winding of the generator, a pressure responsive pile resistor connected in circuit relation with the energizing means disposed to be operated for controlling the voltage generated by the generator, a pressure responsive means disposedfor operating the pile resistor,

a power piston disposed to operate the pressure responsive means, an auxiliary piston disposed to be operated by the power piston, a valve member having a main control valve responsive to the speed of the engine and the operation of the auxiliary piston to control and effect an intermittent operation of the power piston, the intermittent operation of the power piston efiecting a steP-by-step operation of the rheostat to prevent over-control of the excitation of the generator and maintain the speed of the engine substantially constant under changing load conditions.

4. In regulating apparatus for constant speed engines, in combination, a generator provided with an armature winding and a field winding disposed to be driven by the engine, means for energizing the field winding or the generator, a pressure responsive pile resistor connected in circuit relation with the energizing means disposed to be operated for controlling the voltage gener- 'ated by the generator, a pressure responsive means disposed for operating the pile resistor, a power piston disposed to operate the pressure responsive means, an auxiliary piston disposed to be operated by the power piston, a control valve member having a sleeve valve and a piston valve disposed to cooperate in response to a change in the speed of the engine to effect an operation of the power piston, means associated with the sleeve valve responsive to the operation of the auxiliary piston disposed to operate the sleeve valve to stop the operation of the power piston, and means associated with the sleeve valve operating means disposed to permit the operation of the sleeve valve to a position where it cooperates with the piston valve to effect another operation of the power piston, the sleeve valve and piston valve thereby cooperating to effect an intermittent operation of the power piston, the intermittent operation of the power piston efiecting a step-bystep operation of the rheostat to prevent overcontrol of the excitation of the generator and maintain the speed of the engine substantially constant under changing load conditions.

5. In regulating apparatus for constant speed engines having a lubricating system, in combination a generator provided with an armature wind ing and a field winding disposed to be driven by the engine, means for energizing the field winding of the generator, a pressure responsive rheostat connected in circuit relation with the energizing means disposed to beloperated for cont-rolling the voltage generated by the generator, a pressure responsive means disposed for operating the rheostat, a power piston responsive to the lubricant pressure disposed to operate the pressure responsive means, a control valve responsive to the speed of the engine for delivering the lubricant to the power piston, means responsive to the operation of the power piston disposed to operate the control valve to client the intermittent operation of the power piston to give a stepby-step operation of the rheostat to prevent overcontrol of the excitation of the generator, and means associated with the control valve for substantially maintaining it at the temperature of the lubricant in the engine and obtain efiicient operation of the apparatus.

WALTER H. SMITH. 

